Method of and means for thawing



June 8 1926. 1,587,984

E. E.A PEARCE METHOD 0F AND MEANS FOR THAWING Filed Feb. 1. 1923 3Sheets-Sheet 1 {diff/76,5566:

' EMME/UW f June 8 1926.

f E. E. PEARCE METHOD OF AND MEANS FOR THAWING Filed Feb. l

Sheets-Sheet 2 .June 8,1926.- Y 1,587,984

. E. E. Pla-ARCE METHQD OFAND MEANS FOR THAWING v Filed Feb; 1. 192s ssheets-sheet particularly l greater than heretofore possible, thereby inPatented June 8, 1926.

vEDWARD n. rnAnen, or eALnsBUnG, I'Lnrnors.

1 nmn'onoriann Means For ,rHAwrNa v HApplieaton filed February Myinvention relates to ran improve-d method of and means for thawing andmore an improved vmethod of and means for thawing mineral/bearing groundto facilitate the exploitation thereof.

It is an ob'ect of my'invention to provide a method o and means forthawing, the functioning and results of which will -be an improvementover the functioning and results of the methods and means heretoforeprovided. Y i

A more specific object is to increase,'where water, especially coldwater, is employed as the thawing medium, thepenetration of the waterthrough the ground and to eliminate the pinnaeles of frozen ground orso-called frozen collars7 or horses which have heretofore remained afterthe thawing operation. t

A further object of my invention is the provision of a method of Aandmeans for thawing which shall be simple? inexpensive,` and expedient andwhich shall make possible the profitable exploitation of mineral bearingprospects which have heretofore either not been available at all,v orhave had to have been abandoned because they could not be worked withsufficient profit to malrethem worth while. i t i Vhile my presentinvention is not limited to use in connection with such systems it isadapted to be practiced with the cold water point systems of thawingheretofore attempted and provides for securing a more complete anduniform thaw than heretoforel possible with such systems. In addition toproviding for securing a more complete and uniform thaw with suchsystems my present invention provides for making the distancespermissible between the various points creasing the area thawed .with agiven amount of labor kand a given number of points of a given site andwith a` given amount of water at a given pressure or head.

As already stated my present invention is not limited to use with thecold water point systems yof thawing heretofore attempted. I find thathighly satisfactory results may be had by injecting air to agitate ordecrease the inertia of water seeping through the ground eithernaturally or by inducing the vSame -or'by injecting air to agitato or' deereasethe inertia of Water delivered te the grund in any other mannerthan by the point syate1ns-referredtoi In `fact the-n 1, ieee. serialNeteleafio.

jection of yair to agitate or decrease the i ertia of `other thawingfluids or" mediums.y than water lscontemplated within the scope' of myresent invention. ,y y A stil further object of my inventionis todecrease the time 4heretofore required' in thawingl a prospectv ormineral bearing I' shall nowvdescribe my invention con- HQCtlon 4'withthe accompanying drawmgs forming a part ofthe present specificationwhich ydrawings illustratemore orlessdagrammatically certain 'manners ofCarr-ying out the inventiomand certain details which I have foundpractical. It is my belief however, that my present invention is` apioneer one in the art of thawing frozen ground and while they maybehighly desirable, l ydo not therefore intend tohe'limited to suchdetails as'I` may hereinafter electl to describe. i

In the drawings: Figure' l is a vert ing thaw l thawed in my inventionand the substantial configuration of the/.resulting thaw; Figures 3, 4;andjl are diagrammatic vertical sect-ions throughareas of ground showffling other manners olf practioing the teachings of my present invention;

Figure 61s a more or less diagrammatic top Vplan view of an apparatuswhich I-have 'foundy highly satisfactory in practicing a' particularembodiment of my invention;

FigureA 8 is `an enlarged'sectional view taken on the line 8f8 of Fig. 7

yaccordance with',l the teachings ofy Figure l7 .is a plan view showingthe bridlev arrangement thruwhich each of th'epipes leading fromthe-various. units is connected to ythe points atthe outer ends thereof5 Figure 9 is anenlarged fectional view taken on the line 9-`-9.of Fig.7'; and

Figure 10 is an enlarged sectional view .taken on the `line 10%10 ofFig. 6.

In Figs. l and 2 of thefdrawings,i10 designates the surface of theground. The dot and dash line r1 1 locates Vthe lowerv limit' of the.muck kandthe dot and dash line ,12,

the approximate level of the bedrockgat which the greater percentage ofgold ne;K

reame@ posits are `usual fon.- .r LWth referente new 'to 9 and v10 theparticular apparatus which I have elected to explain the manner ofpracticing the invention with the so-called point systems of thawing,comprises a pipe or conduit 15 which pipe or conduit 15 leads from asource of water supply which source may be elevated as to a ditch on theside of a hill to create a suitable head or a pump or any other suitablemeans may be einployed for creating the desired flow. The pipe 15conveys the water to a coupling 16 from which four units 17, 18, 19 and20 are supplied by way of hose connections 21 and a Y coupling 22.

Each of the units 17, 18, 19 and 20'comprises a main 23 from each ofwhich mains a. plurality of pipes or conduits 24 lead or extend to .andaie connected thru suitable Tsk25 with bridles 26. hose connection 27extends from the opposite end of each of said bridles 26 the free endsof these hose connections 27 being connected as through suitable elbows28 with the so-called points or pipes 29.

In thawing the pipes 29 areinsert-ed into the ground at suitabledistances or intervals. The various points may be inserted by holdingthem upright with the lower end from which the water is discharging orflowing on the surface of the ground, the discharging water thawing themuck or gravel immediately ahead of the point and the pipe beinggradually depressed until the desired depth is atained, usually justbelow f the upper level of the bedrock or in other words, the pipes 29are inserted to approximately the lowest point ybelow the area to bethaw-ed. 0f course, the points may be sunk or inserted in any othersuitable or desired'manner. .The point will usually go down of its ownaccord through ice or muck.

Achole is thus thawed very little larger than the point itself and thewater discharged from the lower inserted end of the pipe graduallyreturns or follows up the sides of the pipe to the surface 10. In thismanner any annular thaw is gradually formed about each linserted point.The points with the water continuously flowing therefrom are left in theground vfrom one to seven days, the water following up the sides ofthevpoints to the surfacemof the ground gradually increasing the widthof the thawed areas. When the thawed area reaches the margin of the area30, (Fig. l) it meets the tha-wed area about the next point andtheoreticaly all ground between the two points should be thawed. I havefound rby actual practice however, that the areas heretofore thawedabout the various. points instead of being substantially cylindrical arefairly large at the bottom of each point and then towards the surface ofthe ground they gradually lessen in their penetration, en-

larging slightly at the surface of the ground, so that the areas thawedby each point take lmore or less the `shape of a ten-pin shown at 30 inF ig. v1. The result is that the thaw of the muck stratum 32 kabove thegravel stratum 33 ,and even in some instances the thaw of the gravelstratum itself does not meet the thaw of the adjacent point. c.

Consequently as in thawing with steam points, numerous pinnacles offrozen ground or so-called frozen collars or horses have close togetherthat the area of least penetra` tion about each point would meet/thearea of least penetration about the adjacent points. prohibitive of theexploitation of the average gold bearing areas,y the working ofa givenarea would be materially slowed up,

the labor necessary would be increased and the greater overlap of thethaw about the lower ends of the points to secure a meeting of the areasof least penetration would be unwarranted.

The cost in such a case would be- According to the theory of myinvention,

I inject air to increase the penetration of the water. I have found byactual practice that by injecting air the water may be violentlyagitated by the pressure of the air and by its tendency to rise to thesurface and mourn tainous seas7 created which materially Vincrease thepenetration of the water through the ground. rl`he injection of airprovides a simple, inexpensive and highly effective method of decreasingthe inertia of the water.

yThe water may of course be made as turbulent as desired.

ployed under a reasonable head or pressure There water alone is emitsaction. is very sluggish. To increase the water pressure itself requiresagreat deal` more water, which is usually not available and if so onlyYat a prohibitive cost. I have found that where water alone is employedit is necessary to double the head and use twice' theamount of water toincrease the efiieiency of the thaw 12%. 1

In the embodiment shown thev opposite ends of the mains 23 are closed.The air is supplied from reservoirs 38 one of which reservoirs issuitably mounted upon each of the mains 23.y This arrangement provides asource of air at least somewhat near the point-s of each of the variousunits. To 'avoid meme@ greaty additionallengths of piping 'the 'air is'injected directly into the uf'ate'r pipes'24 from therespective'reservoirs'38 by means o'f relatively short'tubes 39connected at their opposite l ends to the reservoirs 38 and the adjacentends ofthe pipes`24 afs shown in Figs.

y6 'and 10.

From its point of entrance illtothepipes 24 the afirtrai'fels throughsaidpfipes withr the water toa po'int'just short ofthe T 25 at theopposite end ofthe pipe 24.v t said' point the pipe 24 is provided with-a suitable bend 40 or, gooseneck from which 'the air is extracted 'andconveyed by suitable tubes 42 tothe opposite v,ends ofthe bridle 26 asshown in'Figs. l7.8 and v9. In the flow of the vair and 'water thru theconduits'24 the air travels thru thel'uplper port'ionsof'saidco'nf-vduits vand thru the upper portions of the bends or goosenecks 40.Thetubes 'are therefore preferably :connected at the topof the bend 40,afs vshown so that-'the majorpor'- ytion of air will :be extracted orwitl'idrawn at this point. The slugs of air 'are thus with drawn and atthe same time the air is thereby `automatica-lly distributed insubstantially :equal 'portions to the points '29 Y'at the op posite endsof the bridle.l The l'desired dis tributionlo'f 'air to these pointswouldnot be attained ifit were permitted 'to flow with the water by wayof the coupling andthe opposite sides of the' bridle. Valves 45 v areprovided for regulating tor Vadjusting the distribution of airbyw-'ay'of the tubes 42. The gooseneck just described "provides for securingthe desireddistribution ofair to the respective points. l Thisdistribution may however be secured in other ways withinthe scope of 'myinvention. The flow "thru the. conduits 24 may be -regulatec'l 'oradjusted by valves provided therein.

The an1 upon being injected from the tubes 42 into the opposite ends; ofthe bridle 26 flows through the 'hose connections 27 and 'from the lowerends of 'the rvpoints v29 with vthe ywater being ydelivered thereby..This injection yofair decreases the inertiayof the water and increasesthe penetration Consequentlyv the pinnacles of. frozen ground areeliminated and by reason of the greater penetration of the water thepoints may be' spaced further apart than possible yto describe.

heretofore. This increasesthe afre'a thawed with afgrven amountoffla'bor and a given number of 'points 'of agiven' size and with agivenamount of water 'ata given pressure.y The time necessary peet is 'alsodecreased'.y

tov thaw a pro`s- The air and water need not Vbe injected simultaneouslyvinto the points.- They may be 'used :together or the air may bevinjected.

subsequently to the' water.v In fact, the inf jection of air is lasalready stated not limited :to use with thef point 'systems of thawing.i

In Figs. 3, 4 and -5 for example, I'jhave shown 4'my *present inventionembodied lin connectioni'vith the method disclosed in my copendingapplication` Serial No. '4' G,OO2,v liled March 26, 1921. of water iscreated or the seepage increased by sinking a lshaft v60 into theground, the body of water from which the.`flow 'is established beingshown as a shaft 61 `filled with waiter byconveying the same "directlyinto the top 'thereof as 4sh'o'wn,Circulation'v ofthe water to theshaftv 60 may beaided by 'providingl a suitable dam 62. Of course,v thecirculation maybe promoted by a pumpv In these cases aflo'w 63 having asuction pipe v64 arranged with rits intake at the bottom of the shaftj()to-vl vinduce thecirculation'of water to said point,r

at the 'top iofpithel shaft 60 to induce thevr circulationup through themuck stratum f as shown or otherwise'ipos'itioned `inI the' shaftf g j vIn each case the gravel stratum 65 and stratum 66 have been-thawed. InFig. 3

themineral Ibearing portion of the bedrock awateror 'seepage stratum hasformed along r the undersu'rfac'e of the .muck stratum 68.

In either case Ifind that by injecting air asy by means "of a suitablepipe y7() the unifor'mityl and thoroughness of the water pen# etrationkis increased and the uniformity and thoroii-ghnessof the resulting4thaw improved byy the circulation of the air through the vground withthe water as shown, the arrows 7l indicating a flow of water through thevgroundand the dots 72 the v flow or circulation of. air.l The timerequired to thaw a given prospect is decreased and the muck strata whichheretofore have been especially difcult to thaw are thawed thoroughlyand' uniformly.

Itis ofcourse to be understood that there are numerous 'other lwaysofcarrying out the method or processof mypresent invention. Theforegoing descriptions are simply descriptions ofvariousqembodiments ofthe invention as I have actually practiced them.

As already pointedout the invention is not to betalren as limitedv tothe particular de-y tails and arrangements which I have elected 1. Themethod of vthawing ground which IBG consists in utilizing thecirculation oi water.1 through the ground to thaw same and introducingair into the ground ata point belowthe surface thereof to agitatey anddecrease the inertia of the water and increase the penetration of samethrough the ground in a horizontal direction.

The method of thawing ground which consists in utilising the circulationofre'latively cold water through the ground to thaw same and introducingrelatively cold air into the O'roundat a point below the survfacethereo'l' to agitate and decrease the in-A ertia ot' the water andincrease the penetration ot same through the Aground in a vhorizontaldirection. y

3. The method otthawing which comprises delivering water to the area tobe thawed and injecting air to increase the penetration ot the waterhorizontally tlnough the `frozen area.

4i. The n'iethod oit thawing ground which comprises ,introducingrelatively cold water and air into the ground together at a point belowthe surface thereof.v

5.*The method otthawing ground which comprises sinking a shaft thereintoto createa flow or seepage and to iorin a thawed stratum through theground and injecting` air to increase the circulation ci? the iiow orseepage horizontally through said thawed stratum and the penetration oi"the margin ot the saine thru the ground.

f 6. A thawing apparatus comprising a water main, a pair of points, aconduit leading from said main to said points, a source et air, meanstor introducing air from said source into the end ot said conduit`adjacent said main, andmeansfor ertnacting the air from the oppositeend01"' said conduit and distributing the same to said points, said meansincluding a pair of tubes leading from said conduit at said bend` 7. Athawing apparatus comprising, a water main, a source of supplytherefore, a plurality of points, Kconduits leading from said mai-nl tosaid points, an air reservoir 8. In'appa-ratus of theclass described, al

plurality ot' points for introduction into' the ground, water supplymeans for said points,

said points 'permitting V,the discharge of.

water therefrom, and an air supply line for supplying air to said'pointsfor discharge with said water. y, I

9. in apparatus of the class described, a plurality of thawing points, acommon supn ply line for supplying` a thawing fluid yto said points, airsupply means delivering intoy said common supply line and means forevenly distributingthe*air from said common line to said points. i

l0. ln apparatus ot the class described, a plurality of thawing points,a common supply line for supplying ,a thawing fluid to said points, airsupply means delivering into said connnon supply line and means for monline to said points, said means com evenly distril'iuting the air fromsaid com-,-

prising n'ieans for' withdrawing the airy ahead ot the division to thepoints and returning` it beyond said point oi division.

il. lin-combination, a common supply conduit tor a thawing medium, aplurality ot thawing points, a *coupling between said' points and saidconduit, means 4for supply-` ing;r a motive iiuid to said conduit,andmeans ior withdrawing said fluid therefrom and delivering it to thepoints I `beyond said coupling.

12. In apparatus source oit water, a plurality ot pointsLa conduitleading from lsaid source to said points, means for introducing air intosaid conduit and means for `extracting the air from said conduit anddistributing saine to said points.

In Witnesswhereof, I hereunto subscribe my name this 18th' dayoffJanuary, 1923.

. EDVARD E. PEARCE.

the class described,y vav

